i965/vec4: Call calculate_cfg() in test programs to avoid crashing.

Reported-by: Mark Janes <mark.a.janes@intel.com>

src/mesa/drivers/dri/i965/test_vec4_copy_propagation.cpp

@@ -116,6 +116,7 @@ copy_propagation(vec4_visitor *v)
       v->dump_instructions();
    }
 
+   v->calculate_cfg();
    v->opt_copy_propagation();
 
    if (print) {

src/mesa/drivers/dri/i965/test_vec4_register_coalesce.cpp

@@ -119,6 +119,7 @@ _register_coalesce(vec4_visitor *v, const char *func)
       v->dump_instructions();
    }
 
+   v->calculate_cfg();
    v->opt_register_coalesce();
 
    if (print) {